Camber refers to the angle between the plane of a wheel's circumference and a vertical line, measured in degrees and minutes. When the top of a wheel tilts inward, the camber is negative, and when it is tilted outward the camber is positive. Caster refers to the angle between the vehicle's steering axis and a vertical line, as viewed from the side of the wheel. The measurement is in degrees and minutes. Devices to measure and help assist in measuring and setting camber and caster are not new to the art.
U.S. Pat. No. 5,168,632 issued Dec. 8, 1992 to Rimlinger, describes an automotive wheel alignment method and apparatus that has three indicators and a gauge element. This device requires multiple steps to measure and then manipulate the alignment to reach the appropriate level of alignment. The instant device allows the measurement to be taken and then the proper adjustments can be made with the device in constant contact with the vehicle.
U.S. Pat. No. 6,507,988 issued on Jan. 21, 2003 to Riviere discloses a device that attaches to the lugs of the wheel hub and not to the axle, limiting its accuracy.